Thermosetting conductive adhesive

Abstract

A thermosetting conductive adhesive that can exhibit high conductivity (low connection resistance) when cured at a high temperature in a short time. The present invention also provides a thermosetting conductive adhesive that has excellent adhesive strength when cured at a high temperature in a short time. The thermosetting conductive adhesive according to the present invention includes components (A) to (D): component (A): a urethane-modified polyfunctional (meth)acrylate oligomer that is either an aromatic urethane-modified (meth)acrylate oligomer having six (meth)acryl groups in the molecule or an aliphatic urethane-modified (meth)acrylate oligomer having two (meth)acryl groups in the molecule; component (B): a monofunctional (meth)acrylate monomer; component (C): an organic peroxide; and component (D): conductive particles, in which when the component (A) is an aliphatic urethane-modified (meth)acrylate oligomer having two (meth)acryl groups in the molecule, the component (B) is a monofunctional acrylate monomer.

Description

TECHNICAL FIELD[0001]The present invention relates to a thermosetting conductive adhesive, and more specifically to a thermosetting conductive adhesive of which a cured product has isotropic electrical conductivity (conductivity).BACKGROUND ART[0002]Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2011-506751 (US Unexamined Patent Publication No. 2009 / 155597) discloses a conductive adhesive that is B-staged (semi-cured) by light irradiation and then thermally cured, and the conductive adhesive provides photocurability with a (meth)acrylate resin and thermosetting properties with an epoxy resin. In addition, Japanese Unexamined Patent Application Publication No. 2000-256641 discloses an anisotropically conductive adhesive containing an acrylate resin and a thermoplastic resin.SUMMARY OF INVENTION[0003]According to the technique disclosed in Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2011-506751 (US Un...

AI Technical Summary

Benefits of technology

The present invention provides a thermosetting conductive adhesive that has high conductivity and low connection resistance when cured at a high temperature in a short time. Additionally, this adhesive has excellent adhesive strength to an adherend, particularly one with nickel on its outermost surface.

Problems solved by technology

According to the technique disclosed in Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2011-506751 (US Unexamined Patent Publication No. 2009 / 155597), however, light irradiation and thermosetting need to be performed before the conductive adhesive reaches a final cured state, so that two or more curing steps are required, and the conductive adhesive cannot be practically cured in a short time.

Further, the anisotropically conductive adhesive disclosed in Japanese Unexamined Patent Application Publication No. 2000-256641 cannot ensure conductivity unless it is pressed under heating while being sandwiched between adherends having electrodes and is cured with conductive particles sandwiched between electrodes.

Under these conditions, however, there has been a problem in that the conductivity or adhesive force decreases.

The use of the adherend, however, causes troubles of exhibiting high resistance or insufficient adhesive force, so that such troubles needs to be solved.

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